Sample separation/adsorption appliance

ABSTRACT

A sample separation/adsorption appliance ( 100 ) according to one embodiment of the present invention includes: a first buffer solution tank ( 103 ) equipped with a first electrode ( 101 ) and used for holding a first buffer solution; a second buffer solution tank ( 104 ) equipped with a second electrode ( 102 ) and used for holding a second buffer solution; a sample separation section ( 110 ) that holds a sample separation medium ( 131 ) for separating a sample; and a conductive section ( 120 ) that holds a conductive medium ( 133 ), wherein: the sample separation medium ( 131 ) and the conductive medium ( 133 ) are in contact with the sample adsorption member ( 132 ), respectively, on the opposite sides thereof; an end of the sample separation medium ( 131 ) opposite to an end being in contact with the sample adsorption member ( 132 ) is connected to an inside of the first buffer solution tank ( 103 ); and an end of the conductive medium ( 133 ) opposite to an end being in contact with the sample adsorption member ( 132 ) is connected to an inside of the second buffer solution tank ( 104 ). With this arrangement, a sample separation/adsorption appliance that enables efficient transfer of a sample is offered.

This application is the U.S. national phase of International ApplicationNo. PCT/JP2009/059992 filed 1 Jun. 2009, which designated the U.S. andclaims priority to JP Application No. 2008-171272 filed 30 Jun. 2008,the entire contents of each of which are hereby incorporated byreference.

TECHNICAL FIELD

The present invention relates to a sample separation/adsorptionappliance that separates a biological or chemical sample in whichdifferent kinds of components are mixed into these components and thencauses these components to be adsorbed to adsorption members.

BACKGROUND ART

Various kinds of methods have been developed by which samples such asproteins and nucleic acids are separated and detected, taking advantageof their individual properties. Also, apparatuses used for the methodshave been developed. Examples of the separation methods include gelelectrophoresis, capillary electrophoresis, and liquid chromatography.Among these methods, gel electrophoresis has been widely used from theviewpoint of its easiness and realization of high resolution separation.

Gel electrophoresis is carried out in the following modes:electrophoresis by which a sample is separated in only one direction;and two-dimensional electrophoresis by which a sample is separated intwo directions. The two-dimensional electrophoresis is generally carriedout for analysis of proteins.

In a case where a protein is separated by two-dimensionalelectrophoresis, isoelectric focusing electrophoresis that uses a gelstrip having a given pH gradient is used for separation in thefirst-dimensional direction. The isoelectric focusing electrophoresis isa method of applying a voltage across the gel strip to performseparation, taking advantage of differences in isoelectric pointsspecific to proteins. Further, for the separation in thesecond-dimensional direction, SDS-polyacrylamide gel electrophoresis(SDS-PAGE) using sodium dodecyl sulfate (SDS), which is an anionicsurfactant, is widely used. The two-dimensional electrophoresis iswidely used for proteome analysis because it enables separation of manyproteins at once and comprehensive analysis of the proteins. Proteome isthe term that indicates an entire protein into which translation iscarried out in a particular cell, organ, etc. Examples of studies forthe proteome include profiling, functional analysis, etc. of proteins.

Further, it is known that a protein synthesized in vivo is adjusted forits function by being subjected to chemical modification calledpost-translational modification, such as phosphorylation. Theabove-described electrophoresis can only separate a protein intodifferent components. Therefore, only separation analysis is difficultto obtain information regarding post-translational modification of thecomponents.

In proteome analysis, as a method for detecting a sample proteinseparated by electrophoresis, there is a method known as transfer(blotting) by which a sample separated in a gel is adsorbed and fixed toa transfer film. For the transfer film, a nitrocellulose film, a PVDF(Polyvinylidene difluoride) film, or the like film which is easy to bebound to a sample and is highly hydrophobic is used.

The sample having been transferred onto the film is detected with use ofa fluorescent-labeled antibody, probe, or the like. As a method ofdetecting a protein with use of an antibody, Western blotting is known.By overlaying a particular antibody on a film having a proteintransferred thereon, it becomes possible to specify a protein to someextent on the basis of antigen-antibody reaction. As to phosphorylation,which is biologically important post-translational modification, it ispossible to detect the presence or absence of a phosphorylated protein,the differences between phosphorylation sites, and the like byoverlaying an anti-phosphorylated antibody on the film subjected toprotein transfer.

Thus, a combined use of electrophoresis and Western blotting is anextremely effective method for proteome analysis (for example, seeNon-Patent Literature 1).

Conventionally, electrophoresis and Western blotting are carried outmanually by researchers, using separate apparatuses. More specifically,it is general that after SDS-PAGE is carried out in an electrophoresisapparatus, a gel is taken out of the apparatus and moved in a transfer(blotting) apparatus, and then transfer (blotting) is carried out with atransfer film set on the transfer (blotting) apparatus. These operationsare complicated and require some experience because the gel is a verysoft material and therefore difficult to handle. However, there exists atechnique (Patent Literature 1) that automates these operations. PatentLiterature 1 discloses a technique of automating a series of operationsfrom electrophoresis to Western blotting.

CITATION LIST Patent Literature

Patent Literature 1

-   Japanese Patent Application Publication, Tokukai, No. 2007-292616 A    (Publication Date: Nov. 8, 2007)

Non-Patent Literature

Non-Patent Literature 1

-   Protein Experimental Note (II), 3^(rd) edition: From separation and    identification to functional analysis, Yodosha, pp. 38-47 (2005)

SUMMARY OF INVENTION

In many cases, samples for use in analysis, such as proteins for use inproteome analysis and antibodies for use in immunoreaction, aregenerally separated or extracted from cells and tissues at much expensein time and effort. Therefore, in a sample separation/adsorptionappliance for continuously performing a series of operations fromelectrophoresis to Western blotting, there is a demand for a techniquefor more efficiently transferring a sample while minimizing waste.

The present invention has been attained in view the above problems, anda main object of the present invention is to provide a sampleseparation/adsorption appliance that enables efficient transfer of asample.

The inventors of the present invention diligently worked and found thefollowing two problems of the technique disclosed in PatentLiterature 1. One of the problems is that (a) since transfer (blotting)of the sample is carried out in a buffer solution, the buffer solutioncan easily flow into a clearance between a sample separation section anda sample adsorption member during transfer of the sample, and the sampleflows out into the buffer solution in the clearance by self-diffusion.This decreases transfer efficiency of the sample. The other problem isthat (b) when bubbles generated from electrodes by electrochemicalreaction at the time of electrophoresis and transfer (blotting) comesinto contact with the sample adsorption member during transfer of thesample, the sample adsorption member has an area where the sample is nottransferred because no electric current passes through the area. Thiscauses an uneven transfer pattern with spots. After a more thoroughstudy, the inventors of the present invention accomplished the presentinvention.

More specifically, in order to solve the above problems, a sampleseparation/adsorption appliance according to the present inventioncomprises: a first buffer solution tank equipped with a first electrodeand used for holding a first buffer solution; a second buffer solutiontank equipped with a second electrode and used for holding a secondbuffer solution; a sample separation section that holds a sampleseparation medium for separating a sample; and a conductive section thatholds a conductive medium, wherein: a sample adsorption member foradsorbing the sample is installed at a position between the sampleseparation medium and the conductive medium; when the sample adsorptionmember is installed at the position, the sample separation medium andthe conductive medium come into contact with the sample adsorptionmember; an end of the sample separation medium opposite to an end beingin contact with the sample adsorption member is connected to an insideof the first buffer solution tank; and an end of the conductive mediumopposite to an end being in contact with the sample adsorption member isconnected to an inside of the second buffer solution tank.

According to the above arrangement, the first buffer solution is held inthe first buffer solution tank, and the second buffer solution is heldin the second buffer solution tank. This causes the first and secondelectrodes to be electrically connected to each other via the firstbuffer solution, the sample separation medium, the sample adsorptionmember, the conductive medium, and the second buffer solution.Consequently, it is possible to separate the sample in the sampleseparation medium by electrophoresis. Also, it is possible to move theseparated sample by electrophoresis from the sample separation medium tothe sample adsorption member being in contact with the sample separationmedium, so that the sample can be adsorbed to the sample adsorptionmember.

Unlike the conventional technique, movement of the sample from thesample separation medium to the sample adsorption member is carried outoutside the second buffer solution tank. Therefore, it is possible toprevent self-diffusion (outflow) of the sample into the buffer solution.Also, it is possible to prevent the bubbles generated from theelectrodes from reaching the sample adsorption member via the buffersolution. This enables efficient transfer of the sample. This in turn,it is possible to prevent the occurrence of uneven adsorption of thesample, to produce a sharper pattern, and to detect the sample withaccuracy and high sensitivity.

A sample separation/adsorption appliance according to the presentinvention is arranged such that at the end of the sample separationmedium being in contact with the sample adsorption member, the sampleseparation medium has a cut preferably on at least one of upper andlower surfaces thereof, more preferably on both of the upper and lowersurfaces thereof. The cut is provided to make the leading edges thinner.The shape of the cut is not particularly limited as long as the sampleseparation medium and the sample separation section are tapered downtoward their leading edges. Further, a length-to-height ratio of the cutis preferably in a range from ½ to 4.

According to the above arrangement, the sample separation medium hassuch a shape that at the end being in contact with the sample adsorptionmember, tapering of the sample separation medium starts from a certainpoint. According to the later-described findings by the inventors of thepresent invention, such a shape of the sample separation medium can curbthe influence of the wall of the container (the sample separationsection) that immobilizes the sample separation medium.

In a case where the cuts are provided on both of the upper and lowersurfaces of the sample separation medium, the sample separation mediumhas such a shape that it is sharply pointed in a centerward direction ofits one end. According to the later-described findings by the inventorsof the present invention, such a shape of the sample separation mediumcan further curb the influence of the wall.

Further, when the length-to-height ratio of the cut is preferably in therange from ½ to 4, it is possible to further curb the influence of thewall, as described later.

A sample separation/adsorption appliance according to the presentinvention is preferably arranged such that at an end of the sampleseparation section being in contact with the sample adsorption member,the sample separation section has a cut on at least one of upper andlower surfaces thereof.

According to the above arrangement, it is possible to curb outflow ofthe sample caused by a capillary phenomenon that occurs in a clearancebetween the sample separation section and the sample adsorption member.

A sample separation/adsorption appliance according the present inventionis preferably arranged such that a film impregnated with the sampleseparation medium is attached to an end face of the sample separationsection being in contact with the sample adsorption member.

According to the above arrangement, the film provided at the leadingedge of the sample separation section is impregnated with the sampleseparation medium, and the sample separation medium with which the filmis impregnated comes into contact with the sample adsorption member.This makes it possible to bring the sample adsorption member into closecontact with the sample separation medium without causing a clearance.Thus, it is possible to prevent outflow of the sample from the clearanceand to secure a stably energized state.

A sample separation/adsorption appliance according the present inventionis preferably arranged such that a film impregnated with the conductivemedium is attached to an end face of the conductive section being incontact with the sample adsorption member.

According to the above arrangement, the film provided at the leadingedge of the conductive section is impregnated with the conductivemedium, and the conductive medium with which the film is impregnatedcomes into contact with the sample adsorption member. This makes itpossible to bring the sample adsorption member into close contact withthe conductive medium without causing a clearance. Thus, it is possibleto secure a stably energized state.

A sample separation/adsorption appliance according the present inventionis preferably arranged such that at an end of the conductive mediumbeing in contact with the sample adsorption member, the conductivemedium has a cut on at least one of upper and lower surfaces thereof.

Lines of electric force produced on the opposite sides of the sampleadsorption member are formed between the sample separation medium andthe conductive medium. According to the above arrangement, theconductive medium is tapered down. This makes it possible to make thelines of electric force dense. Thus, it is possible to preventelectrical diffusion of the sample at the transfer of the sample and torealize adsorption of the sample with high resolution.

A sample separation/adsorption appliance according the present inventionis preferably arranged such that at an end of the conductive sectionbeing in contact with the sample adsorption member, the conductivesection has a cut on at least one of upper and lower surfaces thereof.

According to the above arrangement, it is possible to curb outflow ofthe sample caused by a capillary phenomenon that occurs in a clearancebetween the conductive section and the sample adsorption member.

A sample separation/adsorption appliance according the present inventionis preferably arranged to further comprise pressing means that pressesat least one of the sample separation medium and the conductive mediumagainst the sample adsorption member.

According to the above arrangement, it is possible to bring the sampleseparation medium, the sample adsorption member, and the conductivemedium into close contact with each other. Thus, it is possible toprevent outflow of the sample from the clearance and to secure a stablyenergized state.

A sample separation/adsorption appliance according the present inventionis preferably arranged to further comprise a third buffer solution tankfor holding a third buffer solution, wherein the sample adsorptionmember is immersed in the third buffer solution.

According to the above arrangement, the sample adsorption member isimmersed in the buffer solution. This makes it possible to secure a morestably energized state.

A sample separation/adsorption appliance according the present inventionis preferably arranged such that the third buffer solution has a pH in arange from 6.0 to 8.5, and more preferably arranged such that each ofthe sample separation medium, the conductive medium, the first buffersolution, and the second buffer solution also has a pH in a range from6.0 to 8.5.

If the third buffer solution is in an acidic pH range or in an alkalinepH range, electroosmotic flow may be generated in the sample adsorptionmember. If the electroosmotic flow is generated, the buffer solution isflown strongly toward the sample adsorption member. This inhibitshigh-resolution adsorption of the sample to the sample adsorptionmember. Further, decrease of the buffer solutions causes an unstableelectrophoresis. According to the above arrangement, a pH of the sampleadsorption member is kept in the neutral range. This makes it possibleto curb the electroosmotic flow. Thus, it is possible to carry outhigh-resolution adsorption of the sample and to maintain stableelectrophoresis.

Note that the electroosmotic flow may occur even in tapered parts of thesample separation medium and the conductive medium. In view of this, thesample separation medium, the conductive medium, and the first andsecond buffer solutions are adjusted to be in a neutral pH range, sothat electroosmotic flows at the tapered parts can be curbed.

A sample separation/adsorption appliance according the present inventionis preferably arranged to further comprise: sample adsorption membermoving means that moves the sample adsorption member in a directionorthogonal to a direction from the sample separation medium to theconductive medium.

According to the above arrangement, a contact point of the sampleadsorption member in contact with the sample separation medium changesto another points as the sample adsorption member moves. Therefore, thesample is continuously adsorbed to the sample adsorption member, and anarea of the sample adsorption on the sample adsorption member variesdepending upon a traveling speed of each sample in the sample separationmedium. By taking advantage of this, it is possible to suitably performvarious analyses.

A sample separation/adsorption appliance according the present inventionis preferably arranged to further comprise: voltage detecting means thatmeasures a voltage between the first electrode and the second electrode;and sample position detecting means that detects movement of the sampleto such a position that the sample separation medium is in contact withthe sample adsorption member, on the basis of the voltage measured bythe voltage detecting means, wherein when the sample position detectingmeans detects movement of the sample to the position, the sampleadsorption member moving means initiates movement of the sampleadsorption member in the direction orthogonal to the direction from thesample separation medium to the conductive medium.

After initiation of the electrophoresis in the sample separation medium,a sample is not adsorbed until a piece in the sample which piece travelsat the fastest speed reaches the leading edge of the sample separationsection (the position at which the sample separation section comes intocontact with the sample adsorption member). Therefore, it is useless tomove the sample adsorption member before initiation of the adsorption ofthe sample.

According to the above arrangement, detection of the sample passingthrough the sample separation section is carried out by monitoring avalue of voltage between the electrodes, so that movement of the sampleadsorption member can be initiated after initiation of adsorption of thesample to the sample adsorption member. More specifically, when thesample reaches the position corresponding to the edge of the taperedpart of the sample separation section by electrophoresis,electroconductivity decreases at the edge of the tapered part. Thisincreases a value of resistance. Therefore, there occurs the phenomenonthat the voltage value increases under the conditions of constantcurrent (Under the conditions of constant voltage, a value of a currentdecreases). In view of this, by monitoring the increase in voltage, itis possible to easily detect initiation of adsorption of the sample tothe sample adsorption member. By initiating movement of the sampleadsorption member on the basis of the above principle, it is possible toefficiently perform adsorption of the sample to the sample adsorptionmember.

A sample separation/adsorption appliance of the present invention isarranged such that a position where the sample separation section comesinto contact with the sample adsorption member is outside the buffersolution tanks in which the electrodes are provided. Therefore, it ispossible to efficiently transfer the sample.

Additional objects, features, and strengths of the present inventionwill be made clear by the description below. Further, the advantages ofthe present invention will be evident from the following explanation inreference to the drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view schematically showing the configuration ofa sample separation/adsorption appliance according to one embodiment(First Embodiment) of the present invention.

FIG. 2 is a cross-sectional view schematically showing the configurationof the sample separation/adsorption appliance according to oneembodiment (First Embodiment) of the present invention.

FIG. 3 is the results of simulations of movements of charged particleswith change in shape of a sample separation medium.

FIG. 4 is an explanatory diagram showing a part where the sampleseparation medium is in contact with a sample adsorption member.

FIG. 5 is a cross-sectional view schematically showing the configurationof a sample separation/adsorption appliance according to one embodiment(Second Embodiment) of the present invention.

FIG. 6 is a graph showing changes in voltage between electrodes withtime from the initiation of electrophoresis.

FIG. 7 is a cross-sectional explanatory view showing an arrangement inwhich a film is provided at the end of the sample separation section inthe sample separation appliance of the present invention.

FIG. 8 is a cross-sectional explanatory view showing an arrangement inwhich a film is provided at the end of the conductive section in thesample separation appliance of the present invention.

DESCRIPTION OF EMBODIMENTS First Embodiment

FIG. 1 is a perspective view schematically showing the configuration ofa sample separation/adsorption appliance 100 according to one embodiment(First Embodiment) of the present invention. FIG. 2 is a cross-sectionalview schematically showing the configuration of the sampleseparation/adsorption appliance 100.

As shown in FIG. 1, the sample separation/adsorption appliance 100includes: a first buffer solution tank 103 equipped with a cathode(first electrode) 101 and used for holding a first buffer solution; asecond buffer solution tank 104 equipped with an anode (secondelectrode) 102 and used for holding a second buffer solution; a sampleseparation section 110 that holds a sample separation medium 131 forseparating a sample; and a conductive section 120 that holds aconductive medium 133.

The sample separation medium 131 and the conductive medium 133 are incontact with a sample adsorption member 132 for adsorbing a sample,respectively, on the opposite sides of the sample adsorption member 132.The sample separation medium 131 is in contact with the sampleadsorption member 132 at an end corresponding to a leading edge 112 ofthe sample separation section 110. The conductive medium 133 is incontact with the sample adsorption member 132 at an end corresponding toa leading edge 122 of the conductive section 120.

At a connection section 111 of the sample separation section 110, an endof the sample separation medium 131 opposite to an end being in contactwith the sample adsorption member 132 is connected to the inside of thefirst buffer solution tank 103. At a connection section 121 of theconductive section 120, an end of the conductive medium 133 opposite toan end being in contact with the sample adsorption member 132 isconnected to the inside of the second buffer solution tank 104.

When buffer solutions are poured into the first buffer solution tank 103and the second buffer solution tank 104, the sample separation medium131, the sample adsorption member 132, and the conductive medium 133 areelectrically connected via the buffer solutions to the cathode 101provided inside the first buffer solution tank 103 and the anode 102provided inside the second buffer solution tank 104. Note that thesample separation/adsorption appliance 100 according to the presentembodiment includes a third buffer solution tank 105 that accommodatesthe sample adsorption member 132 and, is used for holding a third buffersolution. Holding the buffer solution in the third buffer solution tankmakes it possible to prevent drying of the sample adsorption member 132and to more suitably establish electric connection between the cathode101 and the anode 102.

Electric connection between the cathode 101 and the anode 102 enables(i) separation of a sample inside the sample separation medium 131 byelectrophoresis and (ii) transfer of the separated sample to the sampleadsorption member 132 by electrophoresis. In the present embodiment,unlike the conventional technique, transfer of the sample from thesample separation medium 131 to the sample adsorption member 132 iscarried out outside the second buffer solution tank. This makes itpossible to prevent self-diffusion (outflow) of the sample into thebuffer solution and to prevent bubbles generated at the electrodes fromreaching the sample adsorption member 132 by way of the buffersolutions. Thus, it is possible to efficiently transfer the sample whilecutting waste caused by outflow of the sample into the buffer solutionand reducing an uneven transfer pattern of the sample caused by thebubbles. Note that electrophoresis and transfer can be also carried outwith the arrangement in which the sample adsorption member 132 is incontact with the sample separation medium 131 and the conductive medium133 in the buffer solution contained inside the third buffer solutiontank 105. In this case, the presence of the sample separation medium 131and the conductive medium 133 makes it possible to prevent the bubblesgenerated at the electrodes from reaching the sample adsorption member132 by way of the buffer solutions.

The sample separation section 110, which is a member for holding thesample separation medium 131, is fixed onto a stage 140, as shown inFIGS. 1 and 2. The sample separation section 110 can be formed from aninsulating material such as acryl or glass. As shown in FIG. 2, thesample separation medium 131 is filled in the sample separation section110. In this case, the sample separation medium 131 may be filled in thesample separation section 110 before the sample separation/adsorptionappliance 100 is offered. Alternatively, the sample separation medium131 may be filled in the sample separation section 110 by a user of thesample separation/adsorption appliance 100.

The sample separation medium 131 is a medium for separating a sample byelectrophoresis. Examples of the sample separation medium 131 includemedia generally used in electrophoresis, such as polyacrylamide gel andagarose gel. Apart from this, the sample separation medium 131 may benanoscale pillars, the so-called nanopillars, stood up inside the sampleseparation section 110.

The conductive section 120, which is a member for holding the conductivemedium 133, is provided so as to move over the stage 140 in a horizontaldirection, as shown in FIGS. 1 and 2. The conductive section 120 can beformed from an insulating material such as acryl or glass. Theconductive medium 133 is filled in the conductive section 120. In thiscase, the conductive medium 133 may be filled in the conductive section120 before the sample separation/adsorption appliance 100 is offered.Alternatively, the conductive medium 133 may be filled in the conductivesection 120 by the user of the sample separation/adsorption appliance100.

The conductive medium 133 is not particularly limited as long as itcauses only electrolytes to pass through without outflow of the buffersolution so that electrical conductivity is ensured. For example, astructure such as polyacrylamide gel, agarose gel, or nanopillar may befilled in the conductive section 120.

The sample adsorption member 132 is a member for adsorbing a sample. Inthe present embodiment, as shown in FIG. 2, the sample adsorption member132 is immersed in the buffer solution, and upper part of the sampleadsorption member 132 is fixed by a movable arm (sample adsorptionmember moving means) 143.

The sample separation/adsorption appliance may be offered in a statewhere the sample adsorption member 132 is contained therein.Alternatively, the sample separation/adsorption appliance may bearranged such that the sample adsorption member 132 can be filled laterby the user thereof. The sample adsorption member 132 is preferably madefrom a material that ensures strength. For example, if the sample is aprotein, a PVDF (Polyvinylidene difluoride) film or the like may be usedas the sample adsorption member 132. Note that the PVDF film ispreferably subjected to pretreatment for hydrophilicity with methanol orthe like. Alternatively, nylon, nitrocellulose, or conventionally-usedfilm that is prone to binding to nucleic acids or proteins may be usedas the sample adsorption member 132.

The buffer solutions held in the first buffer solution tank 103, thesecond buffer solution tank 104, and the third buffer solution tank 105may be anything as long as they ensure electrical conductivity.Particularly, the buffer solutions are preferably buffer solutions in aneutral pH range. The buffer solutions in a neutral pH range make itpossible to curb generation of electroosmotic flow that results inmovement of the buffer solutions. Particularly, if the buffer solutionheld in the third buffer solution tank 105 is in an acidic pH range orin an alkaline pH range, electroosmotic flow may be generated in thesample adsorption member 132. If the electroosmotic flow is generated,the buffer solution is flown strongly toward the sample adsorptionmember 132. This inhibits high-resolution adsorption of the sample tothe sample adsorption member 132. Further, decrease of the buffersolutions causes an unstable electrophoresis. Adjustment of the buffersolution held in the third buffer solution tank 105 in the neutral pHrange makes it possible to curb the electroosmotic flow. Thus, it ispossible to carry out high-resolution adsorption of the sample andstable electrophoresis.

Note that the electroosmotic flow may occur even in tapered parts of thesample separation medium 131 and the conductive medium 133. In view ofthis, the sample separation medium 131, the conductive medium 133, andthe buffer solutions held in the first buffer solution tank 103 and, thesecond buffer solution tank 104 are adjusted to be in a neutral pHrange, so that electroosmotic flows at the tapered parts can be curbed.

The cathode 101 and the anode 102 may be made from any conductivematerial, but are preferably made from platinum in order to prevent theelectrodes from being ionized.

At the end being in contact with the sample adsorption member 132 (inthe vicinity of the leading edge 112 of the sample separation section110), the sample separation medium 131 preferably has a cut on at leastone of an upper surface and a lower surface thereof. Note that an upwarddirection is a direction orthogonal to a direction from the sampleseparation medium 131 to the sample adsorption member 132. Such a cutcauses the sample separation medium 131 to have such a shape that at theend being in contact with the sample adsorption member 132, tapering ofthe sample separation medium 131 suddenly starts (the sample separationmedium 131 is getting thinner) from a certain point of the sampleseparation medium 131. Note that the cut is provided to make the leadingedge thinner, and the shape of the cut is not particularly limited aslong as the sample separation medium 131 is tapered down toward theleading edge.

That is, the sample separation medium 131 is tapered down only at an endpart that comes into contact with the sample adsorption member 132.After the sample is separated by electrophoresis in the sampleseparation medium 131, the sample is let out from an end face of thesample separation medium 131 and adsorbed (transferred) onto the sampleadsorption member 132. A smaller contact part between sample separationmedium 131 and the sample adsorption member 132 makes a sharper patternof a transferred sample, which allows the appliance according to thepresent embodiment to perform detection of the sample with higherresolution. However, as shown in (a) of FIG. 3, the sample separationmedium 131 that gradually gets thinner from one end toward the other endcauses the sample to come into collision with an inner wall of thesample separation section 110 at separation of the sample byelectrophoresis. This results in uneven sample separation byelectrophoresis.

As shown in (b) of FIG. 3, the sample separation/adsorption appliance100 according to the present embodiment is arranged such that the sampleseparation medium 131 is constituted by (i) a plate-like part where theupper and lower surfaces are parallel to each other and (ii) a taperedpart. With this arrangement, the sample is separated at the plate-likepart and then emitted from the tapered part so that the sample isadsorbed to the sample adsorption member 132. In this manner, only anemission port is tapered. This makes it possible to separate the samplein the sample separation medium 131 with high resolution and to adsorbthe separated sample to the sample adsorption member 132 at highaccuracy.

The shapes of the leading edge of the sample separation medium 131 willbe more specifically described with reference to FIG. 3. FIG. 3 showsthe results of simulations regarding the shapes of the sample separationmedium 131. (a) through (h) of FIG. 3 show lines 150 of electric forceof charged particles that have passed through the sample separationmedia 131 in various forms. For example, (a) of FIG. 3 shows lines 150of electric force of charged particles that have passed through thesample separation medium 131, which is provided in the sample separationsection 110, in a direction from the connection section 111 toward theleading edge 112 (Similarly, (b) through (h) of FIG. 3 show lines ofelectric force of charged particles). Further, values shown in theright-hand parts of (a) through (h) of FIG. 3 each indicates (the numberof charged particles having passed through the sample separation medium131 without coming into collision with the wall surface)/(the number ofcharged particles introduced), in simulation.

For example, the shape of the sample separation medium 131 as shown in(a) of FIG. 3 and described in Patent Literature 1 is such that thesample separation medium 131 is tapered down at a constant rate in thedirection from the connection section 111 toward the leading edge 112.With such a shape, only 1 out of 10 charged particles can pass throughthe sample separation medium 131. On the other hand, the shape of thesample separation medium 131 as shown in (b) of FIG. 3 and described inthe present embodiment is such that only a part near the leading edge112 of the sample separation medium 131 is tapered down. With such ashape, 4 out of 10 charged particles can pass through the sampleseparation medium 131. In this manner, at the end being in contact withthe sample adsorption member 132 (in the vicinity of the leading edge112 of the sample separation section 110), the sample separation medium131 has a cut on at least one of the upper and lower surfaces thereof.This makes it possible to suitably carry out separation of the sample.

The following shows the results of simulations with variously changedlength-to-height ratios of the cut. In (c) of FIG. 3, the ratio was 4.In (d) of FIG. 3, the ratio was 2. In (e) of FIG. 3, the ratio was 1. In(f) of FIG. 3, the ratio was ½. In other words, each of the above valuesis an inverse of a rate of decrease (tilt) of a thickness of the sampleseparation medium 131 relative to a length thereof in the vicinity ofthe leading edge 112. As shown in (c) through (f) of FIG. 3, when theratio is 4 or ½, 7 out of 20 charged particles pass through the sampleseparation medium 131. However, when the ratio is 2 or 1, 8 out of 20charged particles pass through the sample separation medium 131. Thatis, a ratio of a tilt to the width of the sample separation medium 131is most suitably 1 to 2. In terms of an angle of tilt, it is preferablethat the angle of the tilt is on the order of 22.6° to 45°. Further, thelength of a tilt part is preferably short because separation performanceof the sample decreases at the tilt part due to the previously-describedinfluence of the inner wall. Therefore, it is more preferable that theangle of the tilt is on the order of 45°, for example. Note that eventhe shapes satisfying the ratio of 4 or ½ can achieve higher resolutionseparation of the sample than the shape shown in (a) of FIG. 3 and theshape described in Patent Literature 1.

Further, the following will show comparison between the arrangementshown in (g) of FIG. 3 and the arrangement shown in (h) of FIG. 3, i.e.the arrangement in which the emission port of the sample separationmedium 131 is on the upper surface side and the arrangement in which theemission port is in the midsection between the upper and lower surfaces.In (g) of FIG. 3, 8 out of 20 charged particles pass through the sampleseparation medium 131. In (h) of FIG. 3, 9 out of 20 charged particlespass through the sample separation medium 131. Therefore, it is mostsuitable that the emission port of the sample separation medium 131 isin the midsection between the upper and lower surfaces. Thus, the shapeshown in (h) of FIG. 3, i.e. such a shape that both of the upper andlower surfaces of the sample separation medium 131 have cuts, and a partof the sample separation medium 131 in the vicinity of the sampleemission port is tapered down at a tilt angle of approximately 45°toward the midsection between the upper and lower surfaces enableshigher resolution separation of the sample and adsorption (transfer) tothe sample adsorption member.

Further, it is preferable that in the vicinity of the leading edge 112,the shape of the sample separation section 110 itself is also tapered.More specifically, it is preferable that at the leading edge 112, a cutis provided on at least one of the upper and lower surfaces of thesample separation section 110. FIG. 4 shows a contact part where thesample separation section 110 is in contact with the sample adsorptionmember 132. In a state as shown in (a) of FIG. 4, i.e. a state where thecut is not provided, the contact part where the sample separationsection 110 is in contact with the sample adsorption member 132 has alarge area, and a capillary phenomenon occurs in a gap between thesample separation section 110 and the sample adsorption member 132. Thiscauses outflow of the sample 151 from the gap in the direction indicatedby arrows. In view of this, as shown in (b) of FIG. 4, it is preferablethat the sample separation section 110 has the cuts so that the shape ofthe sample separation section 110 is tapered. This makes it possible toprevent outflow (diffusion) of the sample 151 at the contact part wherethe sample separation section 110 is in contact with the sampleadsorption member 132 when the sample 151 has passed through the sampleseparation medium 131 and then emitted from the sample separation medium131.

Note that as in the case with the sample separation section 110, it isalso preferable that a contact part where the conductive section 120 isin contact with the sample adsorption member 132 has a small area sothat the capillary phenomenon is curbed, and it is preferable that atthe leading edge 122 of the conductive section 120, a cut is provided onat least one of the upper and lower surfaces of the conductive section120.

Still further, it is preferable that at the end of the conductive medium133 being in contact with the sample adsorption member 132, theconductive medium 133 has a cut on at least one of the upper and lowersurfaces of the conductive medium 133. The sample adsorption member 132is positioned between the sample separation medium 131 and theconductive medium 133. If both the sample separation medium 131 and theconductive medium 133 are tapered down, it is possible to make lines ofelectric force formed on the opposite sides of the sample separationmedium 131 denser. This makes it possible to prevent electricaldiffusion of the sample at the emission of the sample and to realizeadsorption of the sample with high resolution.

As previously described, the cuts are provided to make the leading edgesthinner. The shape of the cuts is not particularly limited as long asthe sample separation medium 131, the conductive medium 133, the sampleseparation section 110, and the conductive section 120, are tapered downtoward their leading edges. For example, in (c) of FIG. 4, the cutsprovided in the sample separation medium 131 and the sample separationsection 110 are curved. Such a shape also makes it possible to obtainthe same effect.

In one embodiment, as shown in FIG. 7, at the end of the sampleseparation section 110 being in contact with the sample adsorptionmember 132, a film 700 is attached to the leading edge 112 of the sampleseparation section 110. The film 700 is impregnated with the sampleseparation medium 131.

The film 700 is not particularly limited as long as it has a low proteinadsorption property, strength, and narrow through holes. For example,the film 700 can be a hydrophilic PVDF (Polyvinylidene difluoride) film,a hydrophilic PTFE (Polytetra fluoro ethylene) film, a PES (Polyethersulphone) film, or the like film. The film 700 may be attached to thesample separation section 110 with use of an adhesive tape or anadhesive. Alternatively, the sample separation section 110 and the film700 may be held together with use of a clip(s) or the like so that thefilm 700 can be attached to the sample separation section 110. In orderto make the film 700 impregnated with the sample separation medium 131,the film 700 should be attached to the leading edge 112 of the sampleseparation section 110 before the sample separation section 110 isfilled with the sample separation medium 131. For example, assume thatpolyacrylamide gel is used as the sample separation medium 131. In thiscase, an acrylamide solution before gel polymerization should be pouredfrom the connection section 111 of the sample separation section 110with the film 700 attached thereto, after which the gel polymerizationis caused to develop. The presence of a clearance between the sampleseparation medium 131 and the sample adsorption member 132 may causeoutflow of the sample from the clearance. Further, the clearance maycause an unstable passage of electric current, which may in turn causeirregular transfer of the sample. With attachment of the film 700 to thesample separation section 110 and impregnation of the film 700 with thesample separation medium 131, it becomes possible that even the leadingedge 112 of the sample separation section 110 is easily filled with thesample separation medium 131. This makes it possible to bring the sampleadsorption member 132 into close contact with the sample separationmedium 131 without causing a clearance. Thus, it is possible to preventoutflow of the sample from the clearance and to secure a stablyenergized state.

In another embodiment, as shown in FIG. 8, at the end of the conductivesection 120 being in contact with the sample adsorption member 132, afilm 800 is attached to the leading edge 122 of the conductive section120. The film 800 is impregnated with the conductive medium 133.

The film 800 is not particularly limited as long as it has strength andnarrow through holes. For example, the film 800 can be a PVDF film, ahydrophilic PVDF film, a PTFE film, a hydrophilic PTFE film, a PES film,or the like film. The film 800 may be attached to the conductive section120 with use of an adhesive tape or an adhesive. Alternatively, theconductive section 120 and the film 800 may be held together with use ofa clip(s) or the like so that the film 800 can be attached to theconductive section 120. In order to make the film 800 impregnated withthe conductive medium 133, the film 800 should be attached to theleading edge 122 of the conductive section 120 before the conductivesection 120 is filled with the conductive medium 133. For example,assume that polyacrylamide gel is used as the conductive medium 133. Inthis case, an acrylamide solution before gel polymerization should bepoured from the connection section 121 of the conductive section 120with the film 800 attached thereto, after which the gel polymerizationis caused to develop. The presence of a clearance between the conductivemedium 133 and the sample adsorption member 132 may cause an unstablepassage of electric current, which may in turn cause irregular transferof the sample. With attachment of the film 800 to the conductive section120 and impregnation of the film 800 with the conductive medium 133, itbecomes possible that even the leading edge 122 of the conductivesection 120 is easily filled with the conductive medium 133. This makesit possible to bring the sample adsorption member 132 into close contactwith the conductive medium 133 without causing a clearance. Thus, it ispossible to secure a stably energized state.

The conductive section 120 is moved by a movable arm (pressing means)144 and pressed against the sample adsorption member 132. This bringsthe sample adsorption member 132 into close contact with both the sampleseparation medium 131 and the conductive medium 133, which securesenergization.

The sample separation medium 131 may be installed in the sampleseparation section 110 in such a state that the sample separation medium131 contains a sample to be separated. Alternatively, the sample may beadded to the sample separation medium 131 after the sample separationmedium 131 is installed in the sample separation section 110. The sampleis not particularly limited, but the sample can be a prepared productderived from a biological material (e.g. biological body, body fluid,cell strain, tissue culture, or tissue section), a commerciallyavailable reagent, or the like. The sample is more preferablypolypeptide or polynucleotide.

At the time of adding the sample, for example, in two-dimensionalelectrophoresis, a gel strip 130 having undergone isoelectric focusingelectrophoresis in the first dimension is connected to (brought intocontact with) the sample separation medium 131 at a positioncorresponding to the connection section 111 of the sample separationsection 110. The gel strip 130 may be a commercially available gelstrip. Since a gel strip is generally thin and flexible, the gel stripis preferably fixed with use of a support plate 142 formed from acryl orthe like material. The fixed gel strip 130 with the support plate 142 ismoved by the movable arm 141 so as to be connected to the sampleseparation medium 131 inside the sample separation section 110. Notethat the movable arm 141 may double as the movable arm 143. In thiscase, the movable arm 141 operates in the following manner. The movablearm 141 connects the gel strip 130 to the sample separation medium 131.After the sample gets into the sample separation medium 131, the movablearm 141 moves to catch an upper part of the sample adsorption member132.

An electrophoretic separation system used in the first dimension may beincorporated into the appliance according to the present embodiment. Inthis case, it is possible to automate operations from the isoelectricfocusing electrophoresis in the first dimension to the electrophoreticseparation in the second dimension and transfer.

In a case where the electrophoresis in the first dimension is notcarried out, a well (concavity) is formed at the time of filling thesample separation section 110 with the sample separation medium 131.After the sample is introduced into the well, the sample is immobilizedwith agarose gel or the like in order to prevent outflow of the sampleinto the first buffer solution tank 103 (the sample may be introducedtogether with the agarose gel so that the sample is solidified in thewell). As in the case with a normal SDS-PAGE, the well (concavity) canbe formed as follows. That is, a gel monomer solution (a liquid beforechanged to gel by polymerization) is poured into the sample separationsection 110. Before gel monomer polymerization occurs, a comb (usually,a comb-like plate with teeth each about 5 mm long) is inserted. Aftergelation, the comb is removed to complete the well.

After the sample introduction, an electric current is passed between thecathode 101 and the anode 102, which makes it possible to carry outelectrophoretic separation. The electric current is preferably 50 mA orlower, more preferably in the range from 20 mA to 30 mA. When theelectric current is in the above range, it is possible to curb heatgeneration while electrophoresis is carried out at a sufficient speed.If the electric current is much higher, the electrophoresis becomesfaster. However, a higher electric current causes heat generation, whichmay affect the gel, the sample, a resolution of electrophoreticseparation, and others. Note that in order to prevent heat generation, acooling system using a peltier device or the like may be provided in theappliance according to the present embodiment.

When the sample reaches the leading edge 112 of the sample separationsection 110, the sample adsorption member 132 is lifted up by themovable arm 143 so that the sample can be continuously adsorbed(transferred) to the sample adsorption member 132. Whether the samplereaches the leading edge 112 of the sample separation section 110 may bedetermined with a previously-stained marker introduced into the sampleor may be determined by monitoring of a voltage value.

As a colored sample, a sample into which, for example, BPB (BromphenolBlue) is introduced can be preferably used. The BPB is used as afrontline usually indicating a leading edge of electrophoresis in acommercially available molecular-weight marker, a SDS-PAGE kit, or thelike.

For monitoring of a voltage value, for example, a well-known, commonlyused voltage monitor (voltage detecting means) is used that monitors avoltage between the cathode 101 and the anode 102. When the samplereaches the leading edge 112 of the sample separation section 110,electroconductivity decreases at the position where the sampleseparation medium 131 is connected to the sample adsorption member 132.This increases a value of resistance between the electrodes andtherefore sharply increases a voltage value. Monitoring such a voltagevalue enables detection of emission of the sample.

By incorporating a program (sample position detecting means) formonitoring a voltage value into the appliance according to the presentembodiment, it is possible to automatically detect emission of thesample and control the movable arm 143 so that the movable arm 143 liftsup the sample adsorption member 132. In this manner, it is possible tocontrol lifting of the sample adsorption member 132 by a current valueor a voltage value. In the same manner, it is possible to control aspeed of lifting which is carried out after the initiation ofadsorption. This makes it possible to use the sample adsorption member132 without waste (to minimize an area where the sample is not adsorbedin the sample adsorption member 132), and it is possible to downsize theappliance. The speed of lifting should be such a speed that enablesadsorption of the sample with sufficient resolution, and the speed oflifting can be appropriately determined by a person skilled in the art.

After completion of the sample adsorption, the sample adsorption member132 is collected by the movable arm 143 and is subjected to staining,immunoreaction, etc. Thereafter, a separation and transfer pattern ofthe sample is detected by a fluorescence detector or the like. A systemfor fluorescence detection may be also incorporated into the applianceaccording to the present embodiment in order to automate all theoperations, i.e. electrophoresis, transfer, and detection.

Second Embodiment

FIG. 5 is a cross-sectional view schematically showing the configurationof a sample separation/adsorption appliance 200 according to anotherembodiment (Second Embodiment) of the present invention. In the sampleseparation/adsorption appliance 100 according to First Embodiment, thesample adsorption member 132 moves vertically. However, in the sampleseparation/adsorption appliance 200 according to the present embodiment,a sample adsorption member 232 moves horizontally, as shown in FIG. 5.Details of the components are similar to those of the components inFirst Embodiment. The following will describe differences from thecomponents in First Embodiment.

As shown in FIG. 5, a stage 240 of the sample separation/adsorptionappliance 200 includes: a third buffer solution tank 205 thataccommodates the sample adsorption member 232 and is used for holding abuffer solution; a conductive section 220 that holds a conductive medium233; and a second buffer solution tank 204 which is connected to theconductive medium 233 and in which an anode (second electrode) 202 isplaced. The conductive medium 233 and the second buffer solution tank204 are connected to each other via a connection section 222 of theconductive section 220. The conductive section 220 has a shape thatallows it to stand upright. The conductive section 220 is provided witha leading edge 221 that expose the conductive medium 233, at the upperpart of the conductive section 220 which upper part is at an opposedlocation to the connection section 222.

Further, a movable arm (pressing means) 244 is equipped with: a firstbuffer solution tank 203 for holding a first buffer solution; and asample separation section 210 that holds a sample separation medium 231.In the first buffer solution tank 203, a cathode (first electrode) 201is placed. The sample separation medium 231 and the first buffersolution tank 203 are connected to each other via a connection section212 of the sample separation section 210. The sample separation section210 has a shape that allows it to stand upright. The sample separationsection 210 is provided with a leading edge 211 that exposes the sampleseparation medium 231, at the lower part of the sample separationsection 210 which lower part is at an opposed location to the connectionsection 212.

The sample adsorption member 232 is pulled out of the third buffersolution tank 205 by a movable arm (sample adsorption member movingmeans) 243 and passes through a guide roll 245 so as to be in ahorizontal position. Then, the sample adsorption member 232 comes intocontact with the sample separation medium 231 and the conductive medium233 in such a state so as to be positioned between the sample separationmedium 231 and the conductive medium 233. A movable arm 244 moves thesample separation section 210 downward. This brings the sampleadsorption member 232 into close contact with both the sample separationmedium 231 and the conductive medium 233, which secures energization.With this arrangement, separation of the sample introduced into thesample separation medium 231 and transfer of the sample to the sampleadsorption member are carried out.

As in the case with the sample separation/adsorption appliance 100according to First Embodiment, introduction of the sample into thesample separation/adsorption appliance 200 can be achieved by variouskinds of methods. As shown in FIG. 5, a gel strip 230 having undergoneelectrophoresis in the first dimension may be connected to the sampleseparation medium 231 with use of a movable arm 241 and a support 242.

As described above, with an arrangement of the sampleseparation/adsorption appliance 200 according to the present embodiment,i.e. the arrangement in which the sample adsorption member is caused tomove horizontally, it is also possible to obtain the effect of thepresent invention.

EXAMPLE

The sample separation/adsorption appliance 100 according to FirstEmbodiment as shown in FIGS. 1 and 2 were prepared. The sampleseparation section 110 was formed from glass and fixed onto the acrylicstage 140. Further, in order to prevent heat generation at theapplication of a voltage, a cooling device (not shown) using a peltierdevice was placed in a space under the operation stage 140.

The sample separation section 110 (70 mm in width, 70 mm in length, and5 mm in thickness) was filled with 10% polyacrylamide gel (60 mm inwidth, 30 mm in length, and 1 mm in thickness) including Tris-HCl bufferof pH 6.8, as the sample separation medium 131. In order to improveresolution, the sample separation section 110 was formed so that thetapered leading edge 112 has a shape tapered down at a tilt angle of45°. Further, the sample emission port of 100 μm in thickness wasprovided in the center of an end face of the leading edge 112, so thatthe sample separation medium 131 was exposed to the outside. On theother end of the sample separation section 110, the first buffersolution tank 103 was provided so as to be full of a buffer solution. Asthe buffer solution, a commercially available MOPS buffer (Invitrogen)of pH 7.3 was used. Into the first buffer solution tank 103, the cathode101 formed from platinum wire was inserted.

Further, the sample adsorption member 132 was inserted into the thirdbuffer solution tank 105, which was provided on the stage 140. The thirdbuffer solution tank 105 was kept full of a buffer solution in whichcommercially available NuPAGE transfer buffer (Invitrogen) of pH 7.2 wasmixed with 20% methanol. That is, the sample adsorption member 132 wasin a state of being immersed into the buffer solution. Further, theupper part of the sample adsorption member 132 was fixed to the movablearm 143. As the sample adsorption member 132, Immobiron PSQ (Millipore),which is a commercially available PVDF film, was used after beingsubjected to pretreatment for hydrophilicity with methanol.

The conductive section 120 (70 mm in width, 50 mm in length, and 5 mm inthickness) was provided in such a manner that it can slide over thestage 140 in a horizontal direction (toward the sample separationsection 131) to make the sample adsorption member 132 positioned betweenthe sample separation section 110 and the conductive section 120. Theconductive section 120 was formed from glass and filled with 10%polyacrylamide gel (60 mm in width, 15 mm in length, and 1 mm inthickness) including Tris-HCl buffer of pH 6.8. The leading edge 122 ofthe conductive section 120 facing the sample separation section 110 wasformed to have a shape that tapered down, which causes lines of electricforce to be dense. This improved resolution of sample adsorption. On theother end of the conductive section 120, the second buffer solution tank104 was provided so as to be full of a buffer solution. As in the casewith the foregoing third buffer solution tank 105, the buffer solutionused was a buffer solution in which commercially available NuPAGEtransfer buffer (Invitrogen) of pH 7.2 was mixed with 20% methanol. Intothe second buffer solution tank 104, the anode 102 formed from platinumwire was inserted.

The conductive section 120 was moved by the movable arm 144, so that thesample adsorption member 132 came into close contact with the sampleseparation medium 131 provided in the sample separation section 110 andthe conductive section 120 provided in the conductive medium 133.

As the sample, SeeBlue Plus2 Pre-stained Standard (Invitrogen)commercially available as a molecular-weight marker was used. At thetime of filling the sample separation section 110 with the sampleseparation medium 131, a well (concavity of 4 mm by 6 mm by 1 mm) waspreviously formed in the sample separation medium 131. After the samplewas introduced into the well, the sample was immobilized with agarosegel in order to prevent outflow of the sample into the first buffersolution tank 103.

After introduction of the sample, a voltage was applied between thecathode 101 and the anode 102, and electrophoretic separation wascarried out for 1 hour under conditions of a constant current of 20 mA.The previously-described sample, SeeBlue Plus2 Pre-stained Standard(Invitrogen), is a colored protein. Electrophoretic separation of thesample was therefore confirmed by visual observation.

FIG. 6 is a time-voltage graph showing changes in voltage with time fromthe initiation of electrophoresis. At an initiation point A,electrophoresis initiated. At a voltage rising point B, it was confirmedby visual observation of movement of the colored sample that the samplereached the leading edge 112 of the sample separation section 110. Avoltage was detected by a voltage measurement equipment connected to theelectrodes. The movable arm 143 was pre-programmed to operate to startlifting at the voltage rising point B, and the movable arm 143automatically started lifting at 12 μ/sec concurrently with the emissionof the sample.

Thereafter, the sample emitted from the sample separation section 110was continuously adsorbed (transferred) to sample adsorption member 132,and the sample adsorption member 132 was collected by the movable arm143.

The present invention is not limited to the aforementioned embodimentsand is susceptible of various changes within the scope of theaccompanying claims. Also, an embodiment obtained by suitablecombinations of technical means disclosed in the different embodimentsare also included within the technical scope of the present invention.

Further, all of the academic literatures and patent literatures listedherein are incorporated by reference herein.

Specific embodiments or examples implemented in the description of theembodiments only show technical features of the present invention andare not intended to limit the scope of the invention. Variations can beeffected within the spirit of the present invention and the scope of thefollowing claims.

INDUSTRIAL APPLICABILITY

The present invention can be used in the field of analysis of biologicalsamples, chemical samples, and the like and in the field of manufactureof appliances for the analysis.

REFERENCE SIGNS LIST

-   100, 200 sample separation/adsorption appliance-   101, 201 cathode (first electrode)-   102, 202 anode (second electrode)-   103, 203 first buffer solution tank-   104, 204 second buffer solution tank-   105, 205 third buffer solution tank-   110, 210 sample separation section-   120, 220 conductive section-   130, 230 gel strip (sample supplying medium)-   131, 231 sample separation medium-   132, 232 sample adsorption member-   133, 233 conductive medium-   140, 240 stage-   141, 241 movable arm-   142, 242 support-   143, 243 movable arm (sample adsorption member moving means)-   144, 244 movable arm (pressing means)-   150 line of electric force-   151 sample-   245 guide roll-   700, 800 film

The invention claimed is:
 1. A sample separation/adsorption appliance,comprising: a first buffer solution tank equipped with a first electrodeand used for holding a first buffer solution; a second buffer solutiontank equipped with a second electrode and used for holding a secondbuffer solution; a sample separation section that holds a sampleseparation medium for separating a sample; and a conductive section thatholds a conductive medium, wherein: a sample adsorption member foradsorbing the sample is installed at a position between the sampleseparation medium and the conductive medium; when the sample adsorptionmember is installed at the position, the sample separation medium andthe conductive medium come into contact with the sample adsorptionmember; an end of the sample separation medium opposite to an end beingin contact with the sample adsorption member is connected to an insideof the first buffer solution tank; an end of the conductive mediumopposite to an end being in contact with the sample adsorption member isconnected to an inside of the second buffer solution tank; the sampleseparation/adsorption appliance further comprising a pressing means thatpresses at least one of the sample separation medium and the conductivemedium against the same adsorption member; and at the end of theconductive section being in contact with the sample adsorption member,the conductive section is tapered.
 2. The sample separation/adsorptionappliance according to claim 1, wherein at an end of the sampleseparation section being in contact with the sample adsorption member,at least one of the sample separation section and the conductive sectionhave a cut on at least one of upper and lower surfaces thereof.
 3. Thesample separation/adsorption appliance according to claim 1, wherein afilm impregnated with the sample separation medium is attached to an endface of the sample separation section being in contact with the sampleadsorption member.
 4. The sample separation/adsorption applianceaccording to claim 1, wherein a film impregnated with the conductivemedium is attached to an end face of the conductive section being incontact with the sample adsorption member.
 5. The sampleseparation/adsorption appliance according to claim 1, furthercomprising: a third buffer solution tank for holding a third buffersolution, wherein the sample adsorption member is immersed in the thirdbuffer solution.
 6. The sample separation/adsorption appliance accordingto claim 5, wherein the third buffer solution has a pH in a range from6.0 to 8.5.
 7. The sample separation/adsorption appliance according toclaim 1, wherein each of the sample separation medium, the conductivemedium, the first buffer solution, and the second buffer solution has apH in a range from 6.0 to 8.5.
 8. The sample separation/adsorptionappliance according to claim 1, further comprising: sample adsorptionmember moving means that moves the sample adsorption member in adirection orthogonal to a direction from the sample separation medium tothe conductive medium.
 9. The sample separation/adsorption applianceaccording claim 8, further comprising: voltage detecting means thatmeasures a voltage between the first electrode and the second electrode;and sample position detecting means that detects movement of the sampleto such a position that the sample separation medium is in contact withthe sample adsorption member, on the basis of the voltage measured bythe voltage detecting means, wherein when the sample position detectingmeans detects movement of the sample to the position, the sampleadsorption member moving means initiates movement of the sampleadsorption member in the direction orthogonal to the direction from thesample separation medium to the conductive medium.
 10. The sampleseparation/adsorption appliance according to claim 1, wherein at the endof the sample separation section being in contact with the sampleadsorption member, at least one of the sample separation medium and theconductive medium have a cut on at least one of upper and lower surfacesthereof.
 11. The sample separation/adsorption appliance according toclaim 10, wherein a length-to-height ratio of the cut is in a range from½ to
 4. 12. The sample separation/adsorption appliance according toclaim 10, wherein the cut is provided on both of the upper and lowersurfaces of the sample separation medium.
 13. The sampleseparation/adsorption appliance according to claim 1, wherein theconductive medium is a gel.